Prof. Dr. Michèle Heurs

Michèle Heurs is a professor at the Institute for Gravitational Physics of LUH, with a background in non-classical laser interferometry and gravitational wave detection. Her group works on quantum radiation pressure noise cancellation schemes using non-classical light sources at high detection frequencies, useful for quantum metrology applications (e.g. interferometric gravitational wave detection) and quantum technology. In the first funding period of the PhoenixD Cluster of Excellence, she focused on the simulation and production of optical metamaterials.

The motivation for this work comes from gravitational wave astronomy. Here, interferometers are used as measurement devices whose performance is limited in part by the thermal noise of the individual components, particularly in the low-frequency range. Even at cryogenic temperatures, as planned for the “Einstein Telescope”, the thermal noise of conventional multilayer coatings on silicon mirrors represents a considerable limitation. At the same time, the absorption of these coatings may only be in the sub-ppm range at the wavelength of 1550 nm under consideration. For this reason, Heurs and her team are developing highly reflective coatings based on meta-surfaces. Here, periodically arranged silicon nanocylinders were simulated and fabricated on a sapphire substrate, which form a highly reflective meta-surface. With an exact arrangement of the nanostructures and neglecting material losses, a reflectivity of 100 % is possible for the design wavelength. The interaction between the electromagnetic field and the electric or magnetic dipole resonances of the Si nanoparticles in the meta-surface is utilised.

The team is currently analysing the first set of manufactured meta-surfaces. The next step is to feed the measurement results back into the simulation environment in order to optimise the surface geometry.